New interactions in the dark sector mediated by dark energy

Cosmological observations have revealed the existence of a dark matter sector, which is commonly assumed to be made up of one particle species only. However, this sector might be more complicated than we currently believe: there might be more than one dark matter species (for example, two components of cold dark matter or a mixture of hot and cold dark matter) and there may be new interactions between these particles. In this paper we study the possibility of multiple dark matter species and interactions mediated by a dark energy field. We study both the background and the perturbation evolution in these scenarios. We find that the background evolution of a system of multiple dark matter particles (with constant couplings) mimics a single fluid with a time-varying coupling parameter. However, this is no longer true on the perturbative level. We study the case of attractive and repulsive forces as well as a mixture of cold and hot dark matter particles

Women’s participation in organisationally-assigned expatriation: an assignment type effect?

This article examines women’s participation in long-term, short-term, rotational and commuter organisationally-assigned expatriation. It explores the effects of assignment length, pattern and accompanied/unaccompanied status on career contribution and home/family life outcomes. This triangulated research draws upon e-mail correspondence with 71 current female expatriates to learn about assignment types undertaken and future assignment intentions; and in-depth, semi-structured interviews with 26 of these assignees, and 14 Human Resource professionals in two case study oil and gas firms. This research is set within the theoretical frame of rational choice which suggests that couples engage co-operatively in their division of labour to maximise lifetime earnings, with women prioritising home and family over career prospects. The research finds that long-term assignments enable women to maximise or achieve high levels of both career and family outcomes. Alternative ‘flexpatriate’ assignments provide lower quality career potential and familial relationships, leading to career and/or family compromise/sacrifice. A model is presented to explain women’s assignment preferences in meeting career and family life objectives, extending rational choice theory into the expatriate context. Increasing use of flexpatriation may inhibit expatriate gender diversity

Evidence for two protein-lipoylation activities in Escherichia coli

AbstractThe lipoate acyltransferase subunits of the 2-oxo acid dehydrogenase complexes are post-translationally modified with one or more covalently-bound lipoyl cofactors. Two distinct lipoate-protein ligase activities, LPL-A and LPL-B, have been detected in E. coli by their ability to modify purified lipoyl apo-domains of the bacterial pyruvate dehydrogenase complex. Both enzymes require ATP and Mg2+, use L-lipoate, 8-methyllipoate, lipoyl adenylate and octanoyl adenylate as substrates, and both activate lipoyl-deficient pyruvate dehydrogenase complexes. In contrast, only LPL-B uses D-lipoate and octanoate and there are differences in the metal-ion and phosphate requirements. It is suggested that LPL-B may be responsible for the octanoylation of lipoyl domains observed previously under lipoate-deficient conditions

A Process for Improving Course Quality based on Mid-Semester Feedback

Proceedings of: First International Conference on Reforming Education, Quality of Teaching and Technology-Enhanced Learning: Learning Technologies, Quality of Education, Educational Systems, Evaluation, Pedagogies (TECH-EDUCATION 2010). Athens, Greece, May 19-21, 2010.Quality control mechanisms are becoming more important in higher educational institutions. Student evaluation of teaching is typically used to obtain feedback from students about a learning experience but its effect in the course may take too long. Fast feedback mechanisms, in exchange, look at obtaining feedback in order to apply corrective measures quickly. In this paper a process is described to obtain feedback from the students about a course, analyze the received results, and identify the most significant aspects. The process has been applied to a course and led to some adjustments that had immediate impact on the course.The authors are truly indebted to Miguel Valero for his guidance during the design of this process. Work partially funded by the Learn3 project, “Plan Nacional de I+D+I TIN2008-05163/TSI”, the Best Practice Network ICOPER (Grant No. ECP-2007-EDU-417007), the Flexo Project “Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica” (Ref. TSI-020301-2008-19), and the “Emadrid: Investigación y desarrollo de tecnologías para el e-learning en la Comunidad de Madrid” project (S2009/TIC-1650).Publicad

Transforming practice, transforming practitioners:reflections on the TQFE in Scotland

This study offers reflections on the TQFE in Scotland as an example of the transformative professional learning model as identified by various authors. The focus of this study is the professional learning of lecturers in Scotland’s colleges. Informed by wider considerations of teacher education more broadly, it will be of particular interest to those supporting a transformative model of professional learning in a variety of educational contexts. The research was undertaken as a collaborative initiative between each of the three universities which offer the TQFE in Scotland. Qualitative data are drawn from former TQFE participants and college mentors, and thematic analysis used to gain further insight from participant interviews. Findings highlight the transformative nature of the TQFE with an impact that is beyond the currency of the TQFE programme duration. The provision of transformative professional learning opportunities is now imperative given various pressures and tensions around the development of educators more generally and within contemporary Scottish Further Education in particular. Such pressures and tensions include: the varied demands within the Professional Standards for Lecturers in Scotland’s Colleges, and the need for professional learning for college lecturers to go beyond a competency or tool-kit based approach and to be sustainable

Re-Focusing - Building a Future for Entrepreneurial Education & Learning

The field of entrepreneurship has struggled with fundamental questions concerning the subject’s nature and purpose. To whom and to what means are educational and training agendas ultimately directed? Such questions have become of central importance to policy makers, practitioners and academics alike. There are suggestions that university business schools should engage more critically with the lived experiences of practising entrepreneurs through alternative pedagogical approaches and methods, seeking to account for and highlighting the social, political and moral aspects of entrepreneurial practice. In the UK, where funding in higher education has become increasingly dependent on student fees, there are renewed pressures to educate students for entrepreneurial practice as opposed to educating them about the nature and effects of entrepreneurship. Government and EU policies are calling on business schools to develop and enhance entrepreneurial growth and skill sets, to make their education and training programmes more proactive in providing innovative educational practices which help and facilitate life experiences and experiential learning. This paper makes the case for critical frameworks to be applied so that complex social processes become a source of learning for educators and entrepreneurs and so that innovative pedagogical approaches can be developed in terms both of context (curriculum design) and process (delivery methods)

Cosmology with massive neutrinos coupled to dark energy

Cosmological consequences of a coupling between massive neutrinos and dark energy are investigated. In such models, the neutrino mass is a function of a scalar field, which plays the role of dark energy. The evolution of the background and cosmological perturbations are discussed. We find that mass-varying neutrinos can leave a significant imprint on the anisotropies in the cosmic microwave background and even lead to a reduction of power on large angular scales

Five-Spin Supramolecule for Simulating Quantum Decoherence of Bell States

We report a supramolecule that contains five spins of two different types and with, crucially, two different and predictable interaction energies between the spins. The supramolecule is characterized, and the interaction energies are demonstrated by electron paramagnetic resonance (EPR) spectroscopy. Based on the measured parameters, we propose experiments that would allow this designed supramolecule to be used to simulate quantum decoherence in maximally entangled Bell states that could be used in quantum teleportation

Equilibrium and stability of neutrino lumps as TOV solutions

We report about stability conditions for static, spherically symmetric objects that share the essential features of mass varying neutrinos in cosmological scenarios. Compact structures of particles with variable mass are held together preponderantly by an attractive force mediated by a background scalar field. Their corresponding conditions for equilibrium and stability are given in terms of the ratio between the total mass-energy and the spherical lump radius, $M/R$. We show that the mass varying mechanism leading to lump formation can modify the cosmological predictions for the cosmological neutrino mass limits. Our study comprises Tolman-Oppenheimer-Volkoff solutions of relativistic objects with non-uniform energy densities. The results leave open some questions concerning stable regular solutions that, to an external observer, very closely reproduce the preliminary conditions to form Schwarzschild black holes.Comment: 20 pages, 5 figure

Modelling Conformational Flexibility in a Spectrally Addressable Molecular Multi-Qubit Model System

Dipolar coupled multi-spin systems have the potential to be used as molecular qubits. Herein we report the synthesis of a molecular multi-qubit model system with three individually addressable, weakly interacting, spin (Formula presented.) centres of differing g-values. We use pulsed Electron Paramagnetic Resonance (EPR) techniques to characterise and separately address the individual electron spin qubits; CuII, Cr7Ni ring and a nitroxide, to determine the strength of the inter-qubit dipolar interaction. Orientation selective Relaxation-Induced Dipolar Modulation Enhancement (os-RIDME) detecting across the CuII spectrum revealed a strongly correlated CuII-Cr7Ni ring relationship; detecting on the nitroxide resonance measured both the nitroxide and CuII or nitroxide and Cr7Ni ring correlations, with switchability of the interaction based on differing relaxation dynamics, indicating a handle for implementing EPR-based quantum information processing (QIP) algorithms